Rubber vulcanization and products thereof



' Patented June 14, 1927.

UNITED STATES PATENT OFFICE.

s'ruaaa' a. moron, or consnonooxan, rnnns nvama, AND YAsUJuno ruxnmo, or BAY CITY, MICHIGAN, nssIGNons, nY-m EsNn ASSIGNMENTS, T cnmns w. BROWN, WILLIAM L. onausn, mnnwannrnronrm, or rrr'rssumn, mamamvsm 3mm vuncmrzarron nun rnonuo'r s rrmanor.

ll'o Iii-swing. l pplication fled April 12, 920,

The invention relates to.-the vulcanization ly, the invention contemplates the use of possible modifications of metal salts of dithiocarbamic acid, set forth in the patent to Y. Nikaido, No.11,513,122, and the use of modifications of the compounds set forth in the patent to Stuart B. Molony, No. 1,-

558,707, which are suitable for the urpose. Such modifications are accomplish b the substitution of elements, groups, or ra icals, either in the place of the metals of the salts,

or the hydrogen of the acids,'or in place of a the hydrogen or alkyl of the amido group, or both; or instance, in the first case the substitution for the hydro n of the acid or for the metals of the metalfic salts, of other elements or groups such as aromatic groups including Fheny naphthalene, anthracene, etc., thus ormingi corresponding salts, i. e., esters, of the dit iocarbamic acids; and in the second case, in the amido group the substitution for the hydrogen or alkyl groups, of other elements or groups, such as phenyl, anthracene, pyridine, cyanogen, the various chlorides, etc., which can be substituted for the hydrogen of the amido group, either in 40 the acids or in the metallic salts or esters.

The esters of the aromatic dithiocarbamic acids can be prepared from the amino am monium salts of the same acid by treatment with iodophenyls, etc., when the base formiIrIIIgIamino ammonium e(group NH,(OH,), or ,,(OH,), is re lac by the ghfinyl etc. groups; or the r forming ,IL)

Serial No. 373,368. Renewed December 18 1920.

group, etc., can be replaced in the same way.

The esters can alsobe prepared from chlorodithioca-rbonic esters and amines.

1 men of +NH oH.),-os +1101 scH; son, The replacement of the alkyl groups in the amido group by hydrogen, phenyl na hthalene, pyridine, etc., can be accomplis ed by the regular methods for-efiecting substi- .tutions in the amido grou Aniline salt of phenyl dit iocarbamic acid may be prepared by mlxing ten partsof carbon bisulphide, twenty arts of analine and five parts of ethyl also 01 and leavin the mixture in a current of cool dessicate air until all the alcohol and excess of carbon bisulphide are evaporated, when the liquid becomes nearly odorless. This liquid is aniline salt of phenyl dithiocarbamic acid which was formed according to the following equation:

mmm

csemmsn SNHoCcHr This compound is very unstable and when treated with 75% alcohol saturated with zinc sulphate, zinc salt of henyl dithiocarbamic acid is precipitated. This salt is quite stable as repeated washings with water has no efiect upon the composition of the compounds. It may be washed with water, filtered,-and dried in a current ofwarm dry air. Other. metallic salts of phenyl dithiocarbamic acid may be obtained in the like manner.

Methyl ester of henyl dithiocarbamic acid ma also be obtained. by mixing phenyl mustar oil and methyl mercaptan according to the following equation:

I NECGHI WsNwmn-os The advantages to be derived from some of these substitutions are the wide r they ive in the melting point not posed) a in the acid or metallic salts, as these are all of comparatively high meltin points; and also the greater ease of manu acture.

The methods of use of the various accelerating agents herein set forth, as to the quantity employed, the time of vulcanization, the heat required and the proportions of zinc oxide, sulphur and other ingredients vary widely. As a specific illustration, we have found that the methyl ester of dimethyl dithiocarbamic acid, whose production has been described herein, may be used in substantially the same way and in the same proportions as the mixture of monomethyl dithiocarbamate of zinc and dimethyl dithiocarbamate of zinc described in said Patent No. 1,513,122 to Y. Nikaido, the formula be- 100 parts by weight of smoked Ceylon.

50 parts by weight of zinc oxide.

5 parts by weight of sulphur.

parts by weight of accelerating agent.

With steam pressure of 50 pounds in a press, a good cure will be obtained in about ten minutes. At three pounds steam pressure a good cure will be obtained in a press in about forty-five minutes.

The terms, aromatic substituted dithiocarbamate and aromatic disubstituted dithiocarbamate as used in the claims, are intended to include the substituted dithiocarbamates containing a heterocyclic radical having an aromatic constituent.

What we claim is:

1. The process of accelerating the vulcanization of rubber by the use of the phenyl ester of phenyl dithiocarbamic acid.

2. The process of vulcanizing rubber-comprising combining with'the same a vulcanizmg agent and an accelerator comprising an aromatic disubstituted dithiocarbamate.

3. Vulcanized rubber having as an ingredient before vulcanization an aromatic disubstituted dithiocarbamate.

4. The process of vulcanizing rubber comprising combining with the same a vulcanizing agent and an accelerator comprising an aromatic substituted dithiocarbamate.

5. Vulcanized rubber having as ingredient before vulcanization an aromatic substituted dithiocarbamate.

STUART B. MOLON'Y. YASUJURO NIKADDO. 

